[PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status

During some profiling I noticed that default_idle causes a lot of
memory traffic. I think that is caused by the atomic operations
to clear/set the polling flag in thread_info. There is actually
no reason to make this atomic - only the idle thread does it
to itself, other CPUs only read it. So I moved it into ti->status.

Converted i386/x86-64/ia64 for now because that was the easiest
way to fix ACPI which also manipulates these flags in its idle
function.

Cc: Nick Piggin <npiggin@novell.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 355d57970ba3..b045c279136c 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -272,9 +272,9 @@ cpu_idle (void)
         /* endless idle loop with no priority at all */
         while (1) {
                 if (can_do_pal_halt)
-                        clear_thread_flag(TIF_POLLING_NRFLAG);
+                        current_thread_info()->status &= ~TS_POLLING;
                 else
-                        set_thread_flag(TIF_POLLING_NRFLAG);
+                        current_thread_info()->status |= TS_POLLING;
 
                 if (!need_resched()) {
                         void (*idle)(void);